1. Field of the Invention
The present invention relates to an electric connection terminal which is receivable in a connector housing or the like.
2. Related Art
FIG. 4 is a perspective view of a conventional electric connection terminal disclosed in Japanese Design Publication No. H1-322A, and FIG. 5 is a sectional view in the state where the same electric connection terminal is used.
The electric connection terminal 1 is a female terminal which has a cylindrical box portion 2 formed at its front end for receiving a male terminal, an electric wire crimping portion 3 formed at its mid-portion, and a sheath crimping portion 4 formed at its rear end. The box portion 2 is constituted by a bottom plate 2a, opposite side plates 2b and 2b, and a top plate 2c which is connected to the respective top ends of the side plates. A spring piece 5 for pressure contacting the male terminal is disposed on the bottom plate 2a.
The spring piece 5 has a middle portion extending in the longitudinal direction of the terminal which is bent convexly upwardly. Additionally, the terminal has an embossed portion 6 which is deformed inwardly in a concave manner. The embossed portion 6 is formed by inwardly depressing an the mid-portion of the top plate 2c opposite to the spring piece 5. The inner surface of this embossed portion 6 acts as a contact surface which faces the spring piece 5 and which comes into contact with the male terminal such that the male terminal is sandwiched therebetween. This embossed portion 6 is provided over the entire width of the top plate 2c and is defined by sloping front and rear surfaces.
The portion to the rear of rear edge 2e of the box portion 2 is an engagement concave portion 7 which is stepped downwardly. A forward end 12a of a lance (which is a flexible engagement arm) 12 extending from the top wall of a terminal reception hole 11 of a connector housing 10 engages with this engagement concave portion 7, so that the electric connection terminal 1 is retained in the chamber of the housing.
Next, the manner in which the electric connection terminal 1 is installed in the chamber of connector housing will be described with reference to FIG. 5. First, the forward end of a conductor 16 of a wire 15 is crimped by the wire crimping portion 3 of the electric connection terminal 1. In this condition, the electric connection terminal 1 is inserted into the terminal reception chamber 11 of the connector housing 10 from the rear. As shown in FIG. 6A, during the insertion of the terminal, the lance 12 is abutted by the top plate 2c of the box portion 2 so as to be bent upwardly, so that the forward end 12a of the lance 12 slides on and contacts with the outer top surface 2c as the box portion 2 moves inwardly, as shown in FIGS. 6B and 6C. When the rear edge 2e of the terminal passes beyond forward end 12a, the lance 12 is restored to its original state elastically, so that the forward end 12a engages the engagement concave portion 7. As can be seen from the foregoing, the upper surface of the top plate 2c of the box portion 2 acts as a guide surface on which the lance 12 slides while contacting therewith.
The problem with this conventional arrangement is as follows. When the terminal includes a concave portion such as the embossed portion 6 on the guide surface (the upper surface of the top plate 2c) in front of the engagement concave portion 7, the lance 12 is partially restored to its original state elastically when the forward end 12a of the lance is received in the concave portion. This can be mistaken by the operator as complete engagement when, in fact, the terminal has not been sufficiently advanced to allow for the lance 12 to engage with the engagement concave portion 7. Accordingly, there is a fear that a worker may not insert the terminal completely into the chamber of the connector housing.